Identification

Description

Valves are elliptic-lanceolate with sub-capitate to capitate ends. The axial area is narrow and straight. The central area is bow-tie shaped, bordered by alternating short and long striae. The striae are uniseriate and strongly radiate in mid-valve, becoming parallel or slightly convergent at the valve ends. Striae are not resolvable under LM, with the exception of a few central striae that may be visible in some specimens. The areolae are small, rounded and number 60-100 in 10 µm. The raphe is straight and filiform, with simple proximal ends. The proximal ends are only slightly expanded; the terminal fissures are curved toward the secondary side of the valve. Polar bars are indistinct, or very slightly developed.

Autecology

Original Description

Description: Valves elliptic-lanceolate with sub-capitate to capitate ends, 7.6-13.3 µm long and 3.3-4.0 µm wide. Axial area narrow and straight. Central area bow-tie-shaped with alternating short and long striae. Transapical striae uniseriate and strongly radiate in mid-valve, becoming parallel or slightly convergent at valve ends, 30-40 in 10 µm around central area, 35-45 in 10 µm from mid-valve to apices. Areolae small, rounded, 60-100 in 10 µm transapically. Striae irresolvable under LM. Raphe straight, filiform, with simple central endings, only slightly expanded, and terminal fissures curved towards secondary side of the valve. A fold can be observed at the junction of the valve face and the mantle. Polar bars indistinct or very slightly developed.

Links

Cite This Page

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Sellaphora pulchra from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)STRAHLER = distribution plot of the Strahler Stream Order SLOPE = stream reach gradient (degrees)W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.PHSTVL = pH measured in a sealed syringe sample (pH units)log_COND = log concentration of specific conductivity (µS/cm)log_PTL = log concentration of total phosphorus (µg/L)log_NO3 = log concentration of nitrate (µeq/L)log_DOC = log concentration of dissolved organic carbon (mg/L)log_SIO2 = log concentration of silicon (mg/L)log_NA = log concentration of sodium (µeq/L)log_HCO3 = log concentration of the bicarbonate ion (µeq/L)EMBED = percent of the stream substrate that is embedded by sand and fine sedimentlog_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.

Sellaphora pulchra

Enache and Potapova 2009

Valves elliptic-lanceolate with sub-capitate to capitate ends

Central area bow-tie shaped

Valves are elliptic-lanceolate with sub-capitate to capitate ends. The central area is bow-tie shaped, bordered by alternating short and long striae. Striae are strongly radiate at the mid-valve, becoming parallel or slightly convergent at the ends. Only a few striae around the central area may be resolved under LM. Polar bars are...